iPhone 4S carrier performance study finds no clear victor

A new study testing data speed, call reliability and voice quality, web browsing and video performance of Apple's iPhone 4S on the three major US carriers finds that AT&T's data speeds are the fastest, while Verizon takes the crown for having the least dropped calls.

Results from a study released on Friday reveal the strengths and weaknesses of the iPhone 4S on the three major cellular carriers in the US, AT&T, Sprint and Verizon, in an attempt to decipher which network boasts the best overall performance for the device, reports Computerworld.

The study by mobile performance analytics firm Metrico Wireless began in October, when all three major networks starting carrying the iPhone 4S, and surveyed data speeds, voice quality and voice call reliability in cities representative of a nationwide aggregate.

Tests were conducted using the company's global measurement system and consisted of over 20,000 web page downloads, 8,000 data download and upload tests both while moving and stationary and 6,000 voice calls. Voice quality was measured using the POLQA speech quality algorithm over the three carriers' networks.

The reported results come from a six-page summary released by Metrico, with the full 54-page report showing that each carrier has strengths in certain areas of operation. The firm sells its studies and findings to carriers and other telecom companies.

Amit Malhorta, Vice President of Marketing at Metrico, is quick to note that the study is not intended to necessarily find a winner among the three carriers, but "to provide objective data on how each carrier performs across important performance categories."

"We wouldn't be out to crown a single device the winner," Malhotra said. "We won't steer people to one phone or the other. We're not really trying to highlight the negatives."

In terms of data speeds, AT&T was the clear leader and had an average stationary download transfer rate of 3,210 Kbps, triple that of its closest competitor Verizon, while Sprint came in a distant third. Web browsing on the AT&T version of the iPhone 4S was also stellar, with load times averaging 1.29 seconds compared to Verizon's 2.60 seconds. Sprint averaged 6.44 seconds for page downloads.

Metrico rated data delivery as "excellent" across the board, though upload data speeds were left unreported.

Data download speeds | Source: Metrico

The iPhone has had trouble with dropped calls in the past and Malhorta said that the 4S is no exception, showing a higher failure rate than the 1.4% industry average. In the test, Verizon had the least amount of dropped calls with 2.1% followed by AT&T and Sprint, with 2.8% and 3.7% respectively.

Uplink voice quality, when an iPhone user speaks, was a strong point for Sprint, scoring a 3.95 out of a possible 5 points with the Perceptual Objective Listening Quality Analysis algorithm Metrico employed for the study. AT&T scored 3.85 and Verizon 3.5. For incoming calls, voice AT&T took the top spot with a score of 3.82, followed by Sprint with 3.72 and Verizon with. 3.55.

Data download speeds | Source: Metrico

When compared with other 3G smartphones in the carriers' lineups, the 4S was found to be a solid performer in terms of low noise and average bluetooth speech quality, but suffered in speakerphone speech quality.

Video performance was found to be fairly equal when Metrico delivered a 300 Kbps, 20 fps clip to the device. However, the firm noted that delivery success dropped somewhat for all three carriers with YouTube video clips.

Malhorta said that one of the intentions for the study was to show how performance problems in one city reported shortly after a phone is launched becomes less relevant over the entire network over time.

"We want to enable informed decisions on the part of subscribers," Malhorta said. "For carriers and OEMs, even though there are new features and functionalities rolling out, they can't forget about the core functions such as voice and data."

I got my new 4S with sprint and I have yet to drop a single call. With AT&T, I was dropping calls constantly. I dropped so many calls, I started an iphoto album of dropped call screen shots. Sprint has been perfectly reliable for me so far. I'm in greater Boston.

I have been on AT&T using an iPhone since the beginning. I switched to Verizon and got the iPhone 4S. There is no comparison. On AT&T I was dropping over 10 calls a day. Now at most I drop one call a day. AT&T coverage in WeHO and Beverly Hills is like Swiss cheese. Not so for Verizon. I don't know what took me so long to switch! Data is fine. It's better here on Verizon because you have to have a signal to download.

Plus what I have of read a out is the advantage on Verizon of getting cheap local sim cards during international travel. Never again will I have to pay AT&T's international rates. I just came back from a week in London and used my iPhone just like I do here. Bill: 35 dollars!!!!

One big factor......where were they testing? Probably somewhere where they had decent signals for all carriers. I live in a place where both Verizon's and ATT's signals are sketchy. I have only 1 bar inside my house, and often have to stand at the porch door to make phone calls -- that is, if I can even make the call successfully!

If Sprint gave me a decent signal at my house, it'd be a better carrier for me, even if the download speeds are 1/3 the rate. It'd probably still beat my iPhone 3GS.

Even when the study seems to favor ATT, Verizon's network is largely better. So if you want the faster connection (and live in a populated area), ATT may be the better one for you. If you want to be able to have good 3G service over a wider area, Verizon may be better for you.

Even when the study seems to favor ATT, Verizon's network is largely better. So if you want the faster connection (and live in a populated area), ATT may be the better one for you. If you want to be able to have good 3G service over a wider area, Verizon may be better for you.

Yeah, Verizon CLAIMS that their network is better. But when you actually see the comparisons, AT&T wins in most locations.

I realize that Verizon is claiming 4G speeds over most of the country, but AT&T's 3G keeps up with Verizon 4G in most places, so that's really moot.

It's pretty well-known that Verizon has wider 3G coverage, but ATT has faster 3G....where you can get it.

Is that really true anymore? Remember, Verizon and Sprint were claiming, accurately I might add, '3G' coverage for their CDMA2000 areas that were 1x which has real world data transmissions averaging 60?100 Kbits/s, which is worse than the '2G' GSM EDGE speeds AT&T had over the country.